Self-propelled, powered roller screed device

ABSTRACT

A self-propelled power roller screed having two generally parallel tubular screed tubes and powered winching means that cooperatively engage winching cables attached to deadman structures to advance the roller screed. Screed tube power means spin each of the screed tubes in a direction opposite a direction of travel of the roller screed to provide a generally smooth finish to the surface of the concrete and to push excess concrete forward as the screed moves along the forms. The winching means is a worm gear dual drum winch powered by a variable speed reversible power drill. A cable sheave is translated along a channel in the frame of the roller screed to effectively lengthen or shorten one of the winching cables to advance one end of the frame faster or slower than the second end of the frame, facilitating movement of the roller screed around curved portions of concrete paving and allowing for angular adjustment of the roller screed for differences that might exist in the winching cables and winching means. The winching means includes a locking mechanism which prevents the roller screed from advancing down a slope. The winch drums are adapted to be selectively disengaged to facilitate rapid advancement of the winching cables.

CROSS-REFERENCE TO RELATED APPLICATIONS

There are no related applications for this application.

FIELD OF THE INVENTION

The present invention pertains to the field of roller screeds and more particularly pertains to a self-propelled powered roller screed which requires only one operator for screeding cementitious material.

BACKGROUND OF THE RELATED ART

Concrete structures are formed by pouring a cementitious material, such as cement and aggregate (referred to herein as concrete) into a form, or other container, and permitting the material to cure under proper conditions. In the case of a concrete pad, such as a floor, foundation, or roadway, concrete is poured onto a ground, or support, surface and contained by forms connected to, and rising above, the ground, or support, surface. The forms are longitudinal members arranged along a border of a desired location for the concrete pad to contain the viscous concrete and provide a guide for the concrete's thickness and to level the top surface of the concrete.

After concrete is poured between forms, it is spread generally evenly between the forms. A screed is then used to remove excess concrete and level the top surface of the concrete so it is even with the forms. Traditionally, several passes of a screed over the concrete were necessary to achieve the desired surface. Precision is required to conform to building codes and to perform quality work.

A very primitive screed, which is still useful on small jobs, is a simple straight edge such as a straight board. A board, long enough to span the forms, is laid on top of each form and thereafter pulled down the length of the forms by workers at each end of the board. This pushes forward excess concrete: excess concrete is concrete that is higher than the top surface of the forms. While quite suitable for small jobs, such a screed is impractical on large jobs because of the work required to move the excess concrete. In addition, like many conventional screeds, it required several operators to maneuver the screed.

A more practical screed for larger jobs is disclosed in Mitchell, U.S. Pat. No. 4,142,816. Mitchell discloses a powered screed having a hydraulic motor to spin a tubular member while the screed is pulled along the forms by two workers, one each located on either side of the forms. As with most rotary screeds, a single tubular member spins in a direction opposite a direction of travel of the screed. By spinning the tube, this screed provides a good surface to the concrete. However, substantial work is required to pull the screed along the forms. The hydraulic motor, spinning the tube, does not assist to propel the screed forward and the heavy concrete that builds up in front of the screed requires a large amount of force to move. In addition, workers located at each end of the Mitchell screed must keep the screed tube substantially perpendicular to the forms—frequently this is a difficult task because of uneven amounts of concrete from side-to-side and unequal strengths of the workers.

Accordingly, there is a need in the industry to provide a powered roller screed that can be easily operated by one operator and which allows for angular adjustment of the roller screed.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, a roller screed is provided having two generally parallel tubular screed tubes axially and rotatably supported on their ends by a frame. The roller screed also has two winching cables cooperatively engaged with the frame proximate opposite ends of the screed tubes and being removably attachable to suitable deadman structures positioned generally forward of the roller screed. The screed tubes rest on top of and span across forms and advance down the length of the forms over the freshly poured concrete by operation of a winch power means which operates a winching means that cooperatively engages the winching cables. Screed tube power means cooperatively engage and axially spin each of the screed tubes in a direction opposite a direction of travel of the roller screed to provide a generally smooth finish to the surface of the concrete and to push excess concrete forward as the screed moves along the forms. By deploying two screed tubes spinning in a direction opposite a direction of travel of the roller screed, a generally smooth finish to the surface of the concrete is obtained faster and easier than with conventional devices employing only one spinning screed tube. Preferably, the winching means is a worm gear dual drum winch and the winch power means is a variable speed reversible power drill engaging the winching means.

In another aspect of the invention, the roller screed includes a cable sheave cooperatively attached to a threaded nut which is slidingly mounted on the frame. The cable sheave is translated along a channel in the frame when an associated sheave power means rotates a threaded shaft mounted on the frame which passes through the threaded nut. The translation of the cable sheave effectively lengthens or shortens one of the winching cables to advance one end of the frame faster or slower than the second end of the frame, facilitating movement of the roller screed around curved portions of concrete paving and allowing for angular adjustment of the roller screed for differences that might exist in the winching cables and winching means.

In another aspect of the invention, the winching means includes a locking mechanism which prevents the roller screed from advancing down a slope.

In another aspect of the invention, the winch drums are adapted to be selectively disengaged from the worm gear to facilitate rapid advancement of the winching cables.

In another aspect of the invention, the screed tube power means is a pair of variable speed reversible power drills engaging the screed tubes.

In another aspect of the invention, the sheave power means is a variable speed reversible power drill.

In another aspect of the invention, the present invention roller screed may be maneuvered manually by a handle located proximate the winch power means. In particular, the handle allows the operator to translate the roller screed generally perpendicularly to the direction of travel of the roller screed.

The above aspects may be performed alone or in combination with the others.

It is therefore an object of the invention to provide a powered roller screed having a plurality of tubular members that spin in a direction opposite a direction of travel of the screed and that can be easily operated by one operator.

It is another object of the present invention to provide a powered roller screed which allows for angular adjustment of the roller screed.

It is yet another object of the present invention to provide a powered roller screed including a locking mechanism which prevents the roller screed from advancing down a slope.

It is yet another object of the present invention to provide a powered roller screed with winching cables that can be rapidly advanced.

These together with other objects of the present invention, along with the various features of novelty which characterize the present invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the present invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated a preferred embodiment of the present invention.

Before explaining the preferred embodiment of the present invention in detail, it is to be understood that the present invention is not limited in its application to the details of construction, to the arrangements of the components set forth in the following description or illustrated in the drawings, or to the methods described therein. The present invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and that will form the subject matter of the invention.

As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the present invention in any way.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a portion of a preferred embodiment of the present invention, illustrating the frame, screed tube power means, without the attached winching means.

FIG. 2 is a side view of a preferred embodiment of the present invention.

FIG. 3 is a fragmentary rear view of a preferred embodiment of the present invention.

FIG. 4 is a fragmentary front view of a preferred embodiment of the present invention.

FIG. 5 is a fragmentary bottom view of the frame of a preferred embodiment of the angular adjustment means of the present invention, showing the cable sheave in a first position.

FIG. 6 is a fragmentary bottom view of the frame of a preferred embodiment of the angular adjustment means of the present invention, showing the cable sheave in a second position.

FIG. 7 is a fragmentary top view of a preferred embodiment of the present invention, showing the winching means and locking means positioning during the screeding operations.

FIG. 8 is a fragmentary top view of a preferred embodiment of the present invention, showing the winching means and locking means positioning between screeding operations, allowing for substantially free spooling of the first drum and second drum and extension of the winch cables.

FIG. 9 is a side view of a winching means and second drum of a preferred embodiment of the present invention, showing the locking means positioning between screeding operations, allowing for substantially free spooling of the first drum and second drum and extension of the winch cables.

FIG. 10 is a side view of a second drum of a preferred embodiment of the present invention, showing the locking means positioning during the screeding operations.

FIG. 11 is a side view of a first drum of a preferred embodiment of the present invention, showing the locking means positioning during the screeding operations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While this present invention is susceptible of embodiments in many different forms, there are shown in the drawings and will be described in detail herein, a preferred embodiment, with like parts designated by like reference numerals and with the understanding that the present disclosure is to be considered as an exemplification of the principles of the present invention, and is not intended to limit the claims to the illustrated preferred embodiment.

As stated, a conventional method of making a concrete pad is to pour concrete onto a surface and between concrete forms. Viscous concrete is poured onto a floor, or ground surface, between two spaced-apart, longitudinal forms. The concrete is spread so that it substantially covers the floor surface and contacts the forms. It is then necessary to screed a top, or exposed, surface of the concrete.

As illustrated in the appended drawings, in FIG. 1 a preferred embodiment of a roller screed 10 of the present invention is shown located atop the forms 14 and includes a frame, generally designated by the numeral 50, which includes a first side portion 56, a second side portion 54, and an intermediate lateral portion 52. The frame portions may be constructed of hollow rectangular aluminum alloy tubing, although it should be readily understood by those skilled in the art that frame portions having various sizes, lengths, shapes and materials of constriction may be substituted. Preferably, support members 60 and 62 are attached between the first side portion 56 the intermediate lateral portion 52 and the a second side portion 54 and the intermediate lateral portion 52, respectively.

In one aspect of the invention, the roller screed 10 includes two screed tube power means 30 and two associated generally parallel, laterally spaced tubular screed tubes 20. Each screed tube power means 30 is mounted inside a generally rectangular, open-ended screed tube power housing 37 via a bolt 36 or other suitable fastener means. One of the screed tube power means 30 is attached to the first side portion 56 and the other screed tube power means 30 is attached to the second side portion 54 of the frame 50 in opposing alignment. Each screed tube power means 30 defines a first opening 32 and a second opening 33 on opposite ends thereof. Each screed tube power housing 37 includes a generally rectangular arm 28 that extends laterally outwardly from the first opening 33 of the screed tube power housing 37 and contains a plate 27 which extends downwardly from the arm 28. Each arm 28 includes a thrust bearing (not shown) fixedly coupled to the respective plate 27 which receives therethrough and axially supports an axle 26 of a dead end 24 of a respective screed tube 20. The live end 22 and dead end 24 of each of the screed tubes 20 is sealed. Each screed tube power means 30 extends through the first opening 32 of each screed tube power housing 37 and cooperatively engages and axially supports a live end 22 of a screed tube 20. The screed tubes 20 are mounted for rotation about their longitudinal axes in generally horizontal, normal orientations.

In the preferred embodiment, each of the screed tube power means 30 is a variable speed reversible power drill, such as a heavy duty right angel drill commercially available from Makita USA Inc., of La Mirada, Calif., as Model No. DA4031, having the handle and front grip removed, operably connected to the live end 22 of a screed tube 20 via a universal joint 29 for rotatably and axially supporting the screed tube 20, although it should be readily understood by those skilled in the art that other power means may be employed without departing from the scope of the invention. Preferably, the screed tube power means 30 are coupled to a power supply (not shown) via power cords 34 and 39. A three-position switch 130 is connected to each screed tube power means 30 and oriented on the first side portion 56 of the frame 50, a first position effecting a first spinning direction of each screed tube 20, a second position effecting no spinning, and the third position effecting a second spinning direction of each screed tube 20. In operation, the screed tube power means 30 are selectively operated at the same or different variable speeds for effecting rotation of both of said screed tubes 20.

In another aspect of the invention, as shown in FIGS. 2-4, the roller screed 10 has two winching cables 64 and 66 cooperatively engaged with a winching means, generally designated by the numeral 80, and directed around guide pulleys 42 mounted on the frame 50 proximate opposite ends of the screed tubes 20 to removable attachment with suitable deadman structures 46. The screed tubes 20 rest on top of and span across forms 14 and advance down the length of the forms 14 over the freshly poured concrete by operation of a winch power means, generally designated by the numeral 70, which operates the winching means 80 that cooperatively engages the winching cables 64 and 66.

Preferably, the winching means 80 includes a worm gear dual drum body 87 mounted in a winch housing 81 having center plates 118 and end plates 83 and 85 defining a first drum 82 and a second drum 84, respectively, and the winching power means 70 is a variable speed reversible power drill having a drill chuck 102, such as a heavy duty right angel drill commercially available from Dewalt Industrial Tool Co. of Baltimore Md., as Model No. DWD 460, engaging the winching means 80, although it should be readily understood by those skilled in the art that other power means may be employed without departing from the scope of the invention. The first drum 82 and second drum 84 are rotatably and axially mounted on a shaft 98 extending through the ends of the first end 93 and the second end 91 of the winch housing 81. In a preferred embodiment of the invention, winching power means 70 may selectively rest upon a drill rest 72 which is an elongated bar which extends generally vertically upwardly from the winch housing 81 and generally laterally to form a concave support. The winching means 80 includes a worm gear 88 having a drill chuck engagement portion 106 and being mounted on the winch housing 81 and a drum gear 86 fixedly attached to the first end 83 of the first drum 82 and positioned in meshing engagement with the worm gear 88, whereby upon actuation of the winching power means 70, said worm gear 88 rotates and meshingly engages with said drum gear 86 thereby causing the drum gear 86, and hence the connected first drum 82 and second drum 84 to spin. Preferably, the winching power means 70 is coupled to a power supply (not shown) via a power cord 71. The winching power means 70 are operatively connected to the winching means 80 for effecting simultaneously advancement of both of sides of the roller screed 10 along the forms 14 at selectively variable speeds.

Although the operation of the machine described above will be apparent to those skilled in the art, a brief discussion of the operation will be given for convenience. In operation, the winching means 80 advances the roller screed 10 along the forms 14 and the screed tube power means 30 cooperatively engage and axially spin each of the screed tubes 20 in a direction opposite a direction of travel of the roller screed 10 to provide a generally smooth finish to the surface of the concrete and to push excess concrete forward as the roller screed 10 advances along the forms. It may be desirable to make additional passes over the concrete to achieve the desired finish.

In another aspect of the invention, as shown in FIGS. 5 & 6, the roller screed 10 includes an angular adjustment means, generally designated by the numeral 140. In the preferred embodiment, the angular adjustment means 140 includes a cable sheave 144 cooperatively attached to a threaded nut (not shown) which is slidingly mounted on the bottom 53 of the intermediate lateral portion 52 of the frame 50. The cable sheave 144 is translated along a channel 148 in the bottom 53 of the intermediate lateral portion 52 of the frame 50 when an associated sheave power means 148 rotates a threaded shaft 149 mounted in the frame 50 which passes through the threaded nut (not shown). Preferably, sheave power means 158 is a battery-operated, variable speed reversible power drill, such as that commercially available from Dewalt Industrial Tool Co. of Baltimore Md., as Model No. DCD780C2, engaging the end 147 threaded shaft 149, although it should be readily understood by those skilled in the art that other power means may be employed without departing from the scope of the invention. The winching cable 64 associated with the second side portion 54 of the frame 50 is connected on one end to a deadman structure 46 and directed through a pulley guide 42 mounted on the second side portion 54 of the frame 50 and around pulley guide 141 mounted on the first side portion 56 of the frame 50 and around the cable sheave 144 and around pulley guide 142 mounted on the first side portion 56 of the frame 50 and connected to the winching means 80. The translation of the cable sheave 144 effectively lengthens or shortens winching cable 64 to advance one end of the frame 50 faster or slower than the other end of the frame 50, facilitating movement of the roller screed 10 around curved portions of concrete paving and allowing for angular adjustment of the roller screed 10 for differences that might exist in the winching cables 64 and winching means 80.

In another aspect of the invention, as shown in FIGS. 7-11, the winching means 80 has locking means 100 for selectively maintaining the worm gear 88 and drum gear 86 in cooperative engagement. The locking means 100 includes a generally planar member 103 pivotally attached to the winch housing 81 proximate the worm gear 88 via a hinge 104 and a generally L-shaped member 112 pivotally attached to the winch housing 81 proximate the end plates 85 of the second drum 84 via a hinge 110.

As shown in FIGS. 7, 10 & 11, during screeding operations, the locking means 100 are oriented in a first position to maintain the worm gear 88 and drum gear 86 in meshing engagement to prevent the roller screed 12 from advancing down a slope. A thumb screw 92 is selectively positioned to extend through the second end 91 of the winch housing 81 to retain the L-shaped member 112 in the first position.

As shown in FIGS. 8 & 9, the locking means 100 are rotated into a second position to allow the worm gear 88 and drum gear 86 to be disengaged allowing for substantially free spooling of the first drum 82 and second drum 84 and extension of the winch cables 64 and 66 between screeding operations.

In another aspect of the invention, the present invention roller screed may be maneuvered manually by a handle 150 located on the first side portion 56 of the frame 50. In particular, the handle 150 allows the operator to translate the roller screed 10 generally perpendicularly to the direction of travel of the roller screed 10.

In another aspect of invention, screed tubes 20 and intermediate lateral portion 52 of the frame 50 may be replaced with screed tubes 20 and intermediate lateral portion 52 of different lengths to change the width of the roller screed 10.

In operation, the screed tubes 20 generally rest on top of and span across forms 14 and advance down the length of the forms 14 over the freshly poured concrete by operation of a winch power means, generally designated by the numeral 70, which operates the winching means 80 that cooperatively engages the winching cables 64 and 66. However, the screed tubes 20 may alternatively rest on top of previously existing concrete or other generally rigid structure on one or both sides of the floor surface which is being poured.

Hence, while the invention has been described in connection with preferred embodiments, it will be understood that it is not intended that the invention be limited to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as disclosed.

As to the manner of usage and operation of the instant invention, same should be apparent from the above disclosure, and accordingly no further discussion relevant to the manner of usage and operation of the instant invention shall be provided.

With respect to the above description then, it is to be realized that the optimum proportions for the elements of the invention, and variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships described in the specification are intended to be encompassed by the present invention.

Therefore, the foregoing is considered illustrative of only the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact method, construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. 

What is claimed is:
 1. A roller screed, comprising: a) a frame, said frame having a first side portion, a second side portion, and an intermediate lateral portion; b) two generally parallel, laterally spaced tubular screed tubes, each screed tube having an axle, a live end, and a dead end; c) two screed tube power means, one of said screed tube power means being attached to said first side portion and one of said screed tube power means being attached to said second side portion in opposing alignment; d) said first side portion rotationally engaging and axially supporting a dead end of one of said respective screed tubes; e) said second side portion rotationally engaging and axially supporting a dead end of one of said respective screed tubes; and f) each of said screed tube power means rotationally engaging and axially supporting a live end of each of said respective screed tubes and being selectively operable to spin each of said screed tubes in a direction opposite a direction of travel of said roller screed to provide a generally smooth finish to the surface of the concrete and to push excess concrete forward as the screed moves along the forms.
 2. The roller screed of claim 1, wherein each of the screed tube power means comprises a variable speed reversible power drill operably connected to each of said live ends of each of said screed tubes.
 3. The roller screed of claim 2 further comprising a three-position switch connected to each of said screed tube power means, said three-position switch having a first position effecting a first spinning direction of each of said screed tubes, a second position effecting no spinning, and a third position effecting a second spinning direction of each of said screed tubes.
 4. The roller screed of claim 3 wherein said screed tube power means are selectively operated at the same or different variable speeds for effecting rotation of both of said screed tubes.
 5. A roller screed, comprising: a) a frame, said frame having a first side portion, a second side portion, and an intermediate lateral portion; a) two generally parallel, laterally spaced tubular screed tubes, each screed tube having an axle, a live end, and a dead end; b) two screed tube power means, one of said screed tube power means being attached to said first side portion and one of said screed tube power means being attached to said second side portion in opposing alignment; c) said first side portion rotationally engaging and axially supporting a dead end of one of said respective screed tubes; d) said second side portion rotationally engaging and axially supporting a dead end of one of said respective screed tubes; e) each of said screed tube power means rotationally engaging and axially supporting a live end of each of said respective screed tubes and being selectively operable to spin each of said screed tubes in a direction opposite a direction of travel of said roller screed to provide a generally smooth finish to the surface of the concrete and to push excess concrete forward as the screed moves along the forms; and f) two winching cables and a winching means, each of said winching cables being cooperatively engaged with said winching means and removably attachable to deadman structures.
 6. The roller screed of claim 5 wherein the winching means comprises a winch power means and an operably connectable worm gear dual drum having a worm gear and a drum gear, said worm gear dual drum defining a first drum and a second drum, said first drum being fixedly attached to said drum gear, and said worm gear being positioned in meshing engagement with said drum gear, whereby upon actuation of said winch power means said worm gear rotates thereby causing said drum gear and said first drum and said second drum to spin.
 7. The roller screed of claim 6 wherein said winch power means comprises a variable speed reversible power drill engaging said worm gear dual drum for effecting simultaneously advancement of both of sides of said roller screed along forms at selectively variable speeds.
 8. A roller screed, comprising: a) a frame, said frame having a first side portion, a second side portion, and an intermediate lateral portion; b) two generally parallel, laterally spaced tubular screed tubes, each screed tube having an axle, a live end, and a dead end; c) two screed tube power means, one of said screed tube power means being attached to said first side portion and one of said screed tube power means being attached to said second side portion in opposing alignment; d) said first side portion rotationally engaging and axially supporting a dead end of one of said respective screed tubes; e) said second side portion rotationally engaging and axially supporting a dead end of one of said respective screed tubes; f) each of said screed tube power means rotationally engaging and axially supporting a live end of each of said respective screed tubes and being selectively operable to spin each of said screed tubes in a direction opposite a direction of travel of said roller screed to provide a generally smooth finish to the surface of the concrete and to push excess concrete forward as the screed moves along the forms; g) two winching cables and a winching means, each of said winching cables being cooperatively engaged with said winching means and removably attachable to deadman structures; and g) angular adjustment means.
 9. The roller screed of claim 8 wherein said angular adjustment means comprises a cable sheave being translatable along said intermediate lateral portion of said frame and one of said winching cables being passed around said cable sheave, whereby translation of said cable sheave effectively lengthens or shortens said one of said winching cables to advance one end of said frame faster or slower than the other end of said frame, facilitating movement of said roller screed around curved portions of concrete paving and allowing for angular adjustment of said roller screed for differences that might exist in said winching cables and said winching means.
 10. The roller screed of claim 6 wherein said winching means further comprises a locking means for selectively maintaining said worm gear and said drum gear in cooperative engagement.
 11. The roller screed of claim 7 wherein said locking means may be disengaged, thereby allowing for substantially free spooling of said first drum and said second drum and extension of the winch cables.
 12. The roller screed of claim 8 wherein said winching means further comprises a locking means for selectively maintaining said worm gear and said drum gear in cooperative engagement.
 13. The roller screed of claim 8 wherein said locking means may be disengaged, thereby allowing for substantially free spooling of said first drum and said second drum and extension of the winch cables.
 14. A roller screed, comprising: a) a frame, said frame having a first side portion, a second side portion, and an intermediate lateral portion; b) two generally parallel, laterally spaced tubular screed tubes, each screed tube having an axle, a live end, and a dead end; c) two screed tube power means, one of said screed tube power means being attached to said first side portion and one of said screed tube power means being attached to said second side portion in opposing alignment; d) said first side portion rotationally engaging and axially supporting a dead end of one of said respective screed tubes; e) said second side portion rotationally engaging and axially supporting a dead end of one of said respective screed tubes; f) each of said screed tube power means rotationally engaging and axially supporting a live end of each of said respective screed tubes and being selectively operable to spin each of said screed tubes in a direction opposite a direction of travel of said roller screed to provide a generally smooth finish to the surface of the concrete and to push excess concrete forward as the screed moves along the forms; g) two winching cables and a winching means, each of said winching cables being cooperatively engaged with said winching means and removably attachable to deadman structures, said winching means comprising a locking means for selectively maintaining said worm gear and said drum gear in cooperative engagement or disengaging said locking means for substantially free spooling of said first drum and said second drum and extension of the winch cables; and h) angular adjustment means; said angular adjustment means comprises a cable sheave being translatable along said intermediate lateral portion of said frame and one of said winching cables being passed around said cable sheave, whereby translation of said cable sheave effectively lengthens or shortens said one of said winching cables to advance one end of said frame faster or slower than the other end of said frame, facilitating movement of said roller screed around curved portions of concrete paving and allowing for angular adjustment of said roller screed for differences that might exist in said winching cables and said winching means. 